Trends in prescription opioid analgesic use in Australia from 2015 to 2022

Background: Recent measures to curb use and harms of pharmaceutical opioids in Australia have reduced dispensings of opioid analgesics for pain, under Australia's Pharmaceutical Benefits Scheme (PBS). But information on trends in private (self-funded) dispensings and public (government-funded) hospital opioids use is not readily available. Our study describes eight-year population-level trends in Australia's prescribed opioid analgesic use, estimating PBS dispensing claims, private dispensings and hospital use. Methods: Our descriptive study used two datasets covering 2015 to 2022: national IQVIA data on all (PBS/private) pharmaceutical sales to community pharmacies, hospitals and other settings, and PBS dispensing claims data for a 10% sample of Australian residents, extrapolated to estimate national PBS claims. We measured total units of each opioid sold/dispensed, converted into oral morphine equivalent milligrams (OME)/1000 population/day. We estimated private dispensings/public hospitals use by subtracting PBS OME from total OME sold. We calculated hospital OME using sales to hospitals. We assessed annual trends using Joinpoint regression. Results: Between 2015 and 2022 total prescribed opioid analgesic use decreased by 21.2 %, from 1231.4 to 970.6 OME/1000/day (-3.4% per year, p < 0.001). Between 2015 and 2022, PBS dispensing claims decreased by -353.4 OME/1000/day, from 1061.7 to 708.4 OME/1000/day (-5.9 % per year; p < 0.001). In contrast, private dispensings/public hospital use increased by +92.5 OME/1000/day, from 169.7 to 262.3 OME/1000/day (+6.7 % per year; p < 0.001). The contribution of private dispensings/public hospital use to total prescribed opioid analgesic use doubled between 2015 and 2022 from 13.8 % to 27.0 %. Opioid use in hospitals remained stable (-1.1 % per year, p = 0.07), accounting for 8 to 10% of total use between 2015 and 2022. Discussion: Prescribed opioid analgesic use declined between 2015 and 2022 because of reductions in PBS dispensing claims. A quarter of the reduction in PBS dispensing claims was offset by use outside the PBS. Our findings indicate a significant increase in private use, reasons for which may include accessing opioids not PBSsubsidised and circumventing PBS restrictions for PBS-subsidised opioids. Comparing multiple data sources provides a comprehensive account of prescribed opioid analgesic use in Australia.